1. Field of the Invention
The present invention relates generally to semiconductor manufacture and more particularly a system for fabricating interposers on semiconductor components.
2. Description of the Related Art
Generally, microelectronic devices include one or more die (i.e., micro integrated circuits formed on a single substrate) having a multitude of die bond pads, a chip body, and an interconnection scheme to connect the pads on the die to a supporting substrate. Generally, the supporting substrate is formed into a package around the die to provide physical protection from contaminates. The combination of these is generally referred to as a “chip package”. Conventional packaging includes packages such as a dual-inline package (DIP), single-inline package (SIP), ball grid array (BGA), and others. Conventionally, dies are formed on substrates, e.g., wafers, in a batch process. A wafer generally contains many dies that are eventually singulated to produce individual dies that are then packaged on the supporting substrates as integrated circuits, which are then mounted on external circuit elements such as printed circuit boards. The printed circuit boards physically support integrated circuits and electrically interconnect the integrated circuits to, for example, other integrated circuits and circuit elements.
The size of integrated circuits is a major concern because the size of each integrated circuit may influence the size of the overall electronic device. Moreover, the size of the integrated circuit influences the distance required between each of the integrated circuits within the device as well as the distance between each integrated circuit and other elements of the integrated circuit. Changes in transmission impedances are directly affected by such distances thereby affecting signal propagation and therefore operating speed of such electronic devices.
Conventionally, to decrease distances between integrated circuits, manufacturers have worked to reduce integrated circuit package size. One such technique involves stacking dies on top of one another. To stack dies often one die is mounted to a supporting substrate using flip-chip mounting techniques. Generally, an interposer is then glued to the backside of the mounted die, e.g., lower supporting die. The interposer is used to mount another upper die thereto, e.g., upper die to form a stack of dies. Such an interposer acts as a mechanical and electrical separation between the upper and lower dies.
Generally, once the upper die is mounted to a top side of the interposer, a wire bonding machine or other wire bonding device is used to form electrical connections between the upper die, lower supporting die, and the supporting substrates. In some cases, a larger die in area is stacked above a lower die such that room is left on the lower die for wire bonding. In such stacking arrangements, a specialized interposer must be used to provide a base for the larger upper die with backing support for the larger upper die, as dies without backing support may be easily cracked during a wire bonding process. Interposers are generally preformed to accommodate different stacking configurations and must be glued or mounted to a supporting die or the upper die for mounting to the lower supporting die.
Such a process of mounting interposers between the upper die and lower die increases manufacturing time and expense. Further, as different interposers may be needed for different die-stack configurations, an interposer having an incorrect thickness and/or material makeup may cause failure of such stacked die. Moreover, storing of interposers having a variety of thicknesses and materials ads to the cost of integrated circuit manufacturing using such stored interposers.
Therefore, what is needed is an apparatus and method to provide interposers on individual electronic circuits in high volume that is efficient, flexible, and economical.